A nano structured surface can be applied as an anti-reflection film, a hydrophilic/superhydrophobic pattern, a nanosensing probe, or a photonic crystal, such that methods for manufacturing the same have a large commercial value. Recently, a laser has been used to write directly on a sputtered phase transition film material (so-called phase transition mastering (PTM)) to form a master disk or a nano patterned mold.
In the PTM process, a substrate is firstly provided. A metal or metal oxide target material of phase transition material is sputtered onto a substrate to form a film by a high vacuum sputtering system. The phase transition between a crystalline state and amorphous state of the film can be controlled, such that the film can be directly written on by a laser beam. The usual sputtered film is a chalcogenide material or a metal oxide. After exposing the film by the laser beam, a film is developed by a specific wet etchant to remove (or reserve) the exposed part of the film. As such, the film is patterned. Afterward, a nickel layer is electroplated on the patterned film. Finally, the nickel layer is separated from the substrate and the patterned film thereon to form a nickel mold.
Therefore, the PTM film needs new equipment to pattern it.